The COVID-19 Market Crash: The Fastest Bear Market in History

On Wednesday 19 February 2020 the S&P 500 closed at 3,386.15, an all-time high. Twenty-five trading sessions later, on Monday 23 March, it closed at 2,237.40 — a 33.9 percent drop that took the index from peak to bear-market low faster than any decline in the 92-year history of the benchmark. The 1929 crash needed 71 trading days to travel the same distance. The 2007–09 slide needed 351. The COVID-19 bear market compressed the entire arc into five weeks, tripped the NYSE Level-1 circuit breaker four times in ten sessions, and broke the Treasury market badly enough that foreign central banks sold US government debt to raise dollars — the opposite of how crises are supposed to work.

What happened between those two closes is a story about market structure, not epidemiology. The virus was the trigger. The cascade was built in.

From Lunar New Year to Lombardy

On 20 January 2020, the first day of Lunar New Year trading in Hong Kong, the Hang Seng fell 2.8 percent as Wuhan health officials confirmed human-to-human transmission of the novel coronavirus. US markets shrugged. The S&P 500 hit a fresh record on 12 February at 3,379, then another on 19 February at 3,386. Volatility, measured by the VIX, sat at 14 — below its long-run average.

The turn came on Monday 24 February, after a weekend in which Italy reported 150 cases and locked down ten towns in Lombardy. The S&P 500 fell 3.4 percent that Monday, 3.0 percent on Tuesday, and finished the week down 11.5 percent. It was the worst week for US equities since the depths of October 2008. The sell-off was orderly by the standards of what came next — volumes heavy but two-sided, bid-ask spreads wide but functioning.

The following Tuesday, 3 March, Jerome Powell convened an unscheduled conference call of the Federal Open Market Committee and cut the federal funds rate by 50 basis points to a range of 1.00–1.25 percent. It was the first intermeeting cut since October 2008. Powell's written statement that morning contained one sentence that the market read as a tell: "The fundamentals of the US economy remain strong. However, the coronavirus poses evolving risks to economic activity." Stocks rallied for twenty minutes, then closed down 2.8 percent. An emergency cut from a central bank that had been describing the expansion as healthy was not reassurance. It was confirmation.

Four Circuit Breakers in Ten Days

The NYSE's market-wide circuit breakers, rebuilt after the 2010 flash crash and calibrated in their current form in 2013, halt trading for 15 minutes when the S&P 500 falls 7 percent from the prior close (Level 1), another 15 minutes at 13 percent (Level 2), and close the market for the day at 20 percent (Level 3). Before 9 March 2020 the Level-1 threshold had never been breached since its creation. In the following ten trading days it tripped four times.

The 9 March trigger had two fathers. Late on Sunday 8 March, after OPEC+ talks collapsed in Vienna, Saudi Arabia announced it would flood the market rather than cut production. Brent crude opened down 31 percent, WTI fell 25 percent, and US energy debt — close to 12 percent of the high-yield index — gapped wider by 400 basis points. By the time the NYSE opening bell rang, S&P 500 futures were already locked limit-down. The cash market halted four minutes into the session.

Three days later, on the morning of 12 March, Donald Trump's Oval Office address the night before had restricted European travel to the United States. The European Central Bank declined to cut rates that morning and Christine Lagarde told reporters, "We are not here to close spreads. This is not the function of the ECB" — a remark that widened Italian BTP-Bund spreads by 60 basis points before her staff walked it back. US markets opened and hit the Level-1 breaker within five minutes of the open. Thursday 12 March closed down 9.5 percent, the worst single session since Black Monday in 1987.

Markets rallied Friday afternoon on rumours of a national emergency declaration. They gave it all back Monday 16 March. After Powell held an unprecedented Sunday-evening press conference — the FOMC had cut the funds rate to 0–0.25 percent and announced $700 billion of new Treasury and MBS purchases — S&P 500 futures opened Sunday night already limit-down. The cash market opened Monday with a trip of the Level-1 breaker at the bell. By the close the index was down 12 percent. Jamie Dimon later wrote in JPMorgan's April 2020 letter to shareholders that the bank was modelling "a bad recession combined with a kind of financial stress similar to the global financial crisis of 2008."

The Treasury Market Breaks

The story that really alarmed policymakers was happening one floor up from the equity desks, in the Treasury market — a $17 trillion bedrock that is supposed to function in every weather. Between Monday 9 March and Wednesday 18 March, it stopped.

In a normal risk-off episode, Treasuries rally as equities fall. Foreign holders pile in, dealer balance sheets expand to absorb the flow, and yields drop. Between 9 and 18 March 2020 the inverse happened. The 10-year yield, which had touched 0.40 percent on 9 March in a flight to safety, rose back to 1.18 percent by the 18th while the S&P 500 was falling another 17 percent. The 30-year bond was down more than six points over the same stretch.

What was happening, as documented in the Hutchins Center paper "Still the World's Safe Haven?" (Duffie, 2020), was a coincident collapse of three distinct forms of forced Treasury selling. Foreign central banks — many of them operating currencies under pressure from the dollar's surge — sold roughly $300 billion of custody holdings at the New York Fed over those two weeks to raise dollar liquidity. Relative-value hedge funds, caught in the unwind of the cash-futures basis trade, dumped another $90 billion. Bond mutual funds meeting redemptions sold what they could, which meant Treasuries.

Dealer balance sheets could not absorb it. The Basel III supplementary leverage ratio, calibrated to make post-2008 banking safer, capped the amount of Treasury inventory a primary dealer could hold against a given capital base. By 12 March the top fifteen dealers were reporting Treasury holdings within a percent of their internal limits. The Bank for International Settlements, in its June 2020 Quarterly Review, called the episode a "dash for cash" and noted that even the most liquid instrument on earth — the on-the-run 10-year US Treasury — was trading with bid-ask spreads six to eight times their normal width (BIS, 2020).

"When Selling Becomes Viral" (Haddad et al., 2021) traced the feedback loop: corporate bond ETFs were trading at double-digit discounts to net asset value, forcing authorised participants to arbitrage by selling the underlying bonds, which pushed spreads wider, which widened the ETF discount, which forced more selling. The same dynamic ran through TIPS, agency MBS, and municipal bonds. On 12 March a primary-dealer trader quoted in the Financial Times said his desk had "no bid for anything that wasn't a direct obligation of the US government — and even those are wobbling."

The Fed Rewrites the Rulebook

On the evening of Sunday 15 March Jerome Powell, flanked by Vice Chair Clarida and Vice Chair for Supervision Quarles, held a video press conference to announce the FOMC's decisions. The federal funds target was cut by 100 basis points to 0–0.25 percent. The Fed committed to "at least $500 billion of Treasury securities and at least $200 billion of agency mortgage-backed securities" in QE. Dollar swap lines with five major central banks were extended and cheapened. Reserve requirements went to zero.

Markets were unimpressed. The 16 March Level-1 trip that followed was the most emphatic repudiation a Fed announcement has ever received. So the central bank went further. The following calendar, compressed into roughly two weeks, maps what the Federal Reserve did next — and why "The Treasury Market in Spring 2020 and the Response of the Federal Reserve" (Vissing-Jorgensen, 2021) would later argue that no peacetime institution had ever expanded its mandate so fast.

The 23 March package was the turning point. For the first time in the Fed's history it committed to buying corporate bonds — primary-market purchases through the PMCCF and secondary purchases through the SMCCF, including investment-grade ETFs. The announcement itself did most of the work: the Fed bought less than $15 billion of ETF shares in total, but the signal that an infinite balance sheet stood behind the corporate-bond market collapsed spreads from more than 400 basis points on 23 March to 150 by early June. The S&P 500 bottomed the same afternoon at 2,237.40, never to revisit that level.

Six days later, on 27 March, Congress passed the $2.2 trillion CARES Act, which included $454 billion of Treasury equity to absorb first-loss risk in the Fed's new facilities — the legal mechanism that allowed Section 13(3) emergency lending to extend into corporate credit and municipal markets. The combination was roughly $5 trillion of monetary and fiscal firepower committed in under two weeks, against a US economy whose nominal annual output was then $21 trillion.

Oil Below Zero and the Retail Surge

The crash had two coda that would have been headline events in any other market environment. On 20 April, with floating storage at Cushing, Oklahoma almost full, the May 2020 WTI crude futures contract closed at −$37.63 per barrel. Paper longs, unable to take physical delivery, paid counterparties to remove the oil. The largest oil ETF, the United States Oil Fund (USO), had been rolling front-month contracts mechanically for years; its forced roll in April amplified the contango into negative prices and the fund restructured under emergency SEC relief the following week.

On the other side of the tape, retail brokerages were seeing account openings at unprecedented rates. Robinhood added three million new funded accounts between March and May. The app's zero-commission model, payment-for-order-flow economics, and gamified interface — combined with lockdown boredom and CARES Act stimulus cheques — produced a retail trading boom that would eventually crystallise in the GameStop short squeeze of January 2021. The echoes of 2020 would run through the market structures explored in the flash crash of 2010 and earlier episodes like Black Monday 1987, each of which had prompted its own round of circuit-breaker redesign.

S&P 500, January to April 2020

Lessons the Plumbing Taught

Steven Mnuchin, addressing reporters on 17 March outside the White House, described the scale of the problem in terms the Treasury Secretary rarely uses in public: "We could be looking at 20 percent unemployment without intervention." The line was not a forecast — it was an argument for the CARES Act to move that week, which it did. Powell, in a rare 60 Minutes interview recorded on 17 May, was more measured. Asked whether the Fed had run out of ammunition, he answered, "There's really no limit to what we can do with these lending programmes."

Both statements were accurate descriptions of the institutional fact that April 2020 had established. The Fed could and did backstop anything it chose to backstop. The subsequent Group of 30 report chaired by Duffie recommended three structural responses that the Fed would go on to implement: expanding central clearing for Treasuries, making SLR relief for Treasury and reserves holdings permanent or semi-permanent, and establishing a Standing Repo Facility — which the FOMC did in July 2021 after two years of deliberation. The Basel Committee paused the implementation of new SLR rules; primary dealers gradually rebuilt inventory capacity; the Treasury market resumed functioning, though with a structural awareness that it had not functioned for two weeks in 2020.

Seven weeks after bottoming, the S&P 500 had retraced more than half of its peak-to-trough loss, closing April at 2,912.43. By August 2020 it had made a new all-time high. The recovery's speed was unprecedented in the other direction — a full bear-market round trip in 131 trading days. Unemployment peaked at 14.7 percent in April, then fell every month for the rest of the year. The shape of the recovery owed far more to the Fed and the CARES Act than to any change in the underlying pandemic, which continued to kill thousands of Americans daily into 2021.

The question that policymakers and academics are still arguing is whether the COVID-19 response established a template or a trap. The Fed now has explicit corporate-bond facilities on the shelf, a FIMA Repo Facility for foreign central banks, and — after 2023 — a Bank Term Funding Program that emerged from the same intellectual reflexes. Each one prices risk lower than a market-clearing rate would. Each one accretes, like the Greenspan put before it, into the prior distribution of what investors believe the central bank will do. The 25-day bear market of February and March 2020 was an episode. The rewriting of the Fed's rulebook that followed is still in force, still expanding, and still without a clear exit.

Powell ended the 15 March Sunday-night press conference with a line that now reads as prophecy: "We are prepared to use our full range of tools to support the flow of credit to households and businesses, and thereby promote our maximum employment and price stability goals." Sixteen words, announced on a Sunday evening to a country that was cancelling flights and stocking pantries, that redrew where the Federal Reserve's balance sheet ends.